Organic light emitting diode display and method for manufacturing the same

ABSTRACT

An organic light emitting diode display comprises a substrate comprising a major surface; first, second, third and fourth electrodes positioned over the substrate; a pixel defining layer positioned over the plurality of electrodes and comprising first, second, third and fourth openings; and a spacer positioned over the pixel defining layer. The first, second, third and fourth openings overlap the first, second, third and fourth electrodes, respectively, when viewed in a viewing direction perpendicular to the major surface. The first, second, third and fourth openings comprise first, second, third and fourth corners, respectively, wherein the first, second, third and fourth corners neighbor one another when viewed in the viewing direction. When viewed in the viewing direction, the spacer comprises at least a portion placed within an imaginary polygon defined by the first, second, third and fourth corners.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean PatentApplication No. 10-2015-0014271 filed in the Korean IntellectualProperty Office on Jan. 29, 2015, the entire contents of which areincorporated herein by reference.

BACKGROUND

(a) Field

The present disclosure relates to an organic light emitting diodedisplay and a method for manufacturing the same.

(b) Discussion of the Related Technology

An organic light emitting diode display includes two electrodes and anorganic light emission layer disposed therebetween. Electrons injectedfrom a cathode combine with holes injected from an anode in the organiclight emission layer to form excitons and emit light while the excitonsemit energy.

The organic light emitting diode display has self-emittingcharacteristics and unlike a liquid crystal display, need not a separatelight source and therefore may be reduced in a thickness and a weight.Further, the organic light emitting diode display is a display whichrepresents high quality characteristics, such as low power consumption,high luminance, and a high response speed and therefore has recentlydrawn much attention.

In embodiments, The above information disclosed in this Backgroundsection is only for enhancement of understanding of the backgroundsection and therefore may contain information that does not form theprior art that is already known in this country to a person of ordinaryskill in the art.

SUMMARY

One aspect of the invention provides an organic light emitting diodedisplay and a method for manufacturing the same having advantages ofincluding a design of a spacer capable of minimizing the probability ofcovering an electrode or preventing the electrode from being covered byinvading debris of a damaged spacer into an opening of a pixel defininglayer even though the spacer is damaged by an external impact.

Another aspect of the invention provides an organic light emitting diodedisplay, which may comprise: a substrate comprising a major surface; aplurality of electrodes positioned over the substrate; a pixel defininglayer positioned over the plurality of electrodes and comprising aplurality of openings, each of which is disposed over and overlaps oneof the plurality of electrodes; and a spacer positioned over the pixeldefining layer, wherein the plurality of electrodes comprises first,second, third and fourth electrodes, wherein the plurality of openingscomprises first, second, third and fourth openings overlapping thefirst, second, third and fourth electrodes, respectively, when viewed ina viewing direction perpendicular to the major surface, wherein thefirst, second, third and fourth openings comprise first, second, thirdand fourth corners, respectively, wherein the first, second, third andfourth corners neighbor one another when viewed in the viewingdirection, wherein, when viewed in the viewing direction, the spacercomprises at least a portion placed within an imaginary polygon definedby the first, second, third and fourth corners.

In the foregoing device, the plurality of electrodes may furthercomprise fifth and sixth electrodes, wherein the plurality of openingscomprise fifth and sixth openings overlapping the fifth and sixthelectrodes, respectively, when viewed in the viewing direction, whereinthe device comprises first and second pixels, each of which comprisesfirst, second and third sub-pixels, the first, second and thirdsub-pixels configured to emit colored light having colors different fromone another, wherein the first, third and fifth openings belong to thefirst, second and third sub-pixels of the first pixel, respectively,wherein the second, fourth and sixth openings belong to the first,second and third sub-pixels of the second pixel, respectively, whereinthe first, second, fifth and sixth openings are arranged such that theirlong sides are substantially parallel to each other when viewed in theviewing direction, wherein the third and fourth openings are arrangedsuch that their long sides are substantially aligned to an imaginarystraight line when viewed in the viewing direction, wherein the firstand fourth corners are diagonally disposed, and the second and thirdcorners are diagonally disposed.

Still in the foregoing device, when viewed in the viewing direction, thespacer does not comprise a portion disposed between the first and secondopenings, between the first and third openings, between the second andfourth openings or between the third and fourth openings. The pixeldefining layer may further comprise a receiving groove which is formedalong a boundary abutting to the pixel defining layer by the spacer toreceive at least a portion of the spacer. Each of the first, second,third and fourth openings has a generally rectangular shape, wherein,when viewed in the viewing direction, the first and second openings arearranged such that their long sides are substantially parallel to afirst direction and the third and fourth openings are arranged such thattheir long sides are substantially parallel to a second direction whichis perpendicular to the first direction. Each of the first, second,third and fourth corners may be rounded. The cross section in which thespacer may be cut in a direction parallel to the major surface of thesubstrate has a shape of any one of a polygon, a circle, a semicircle,and an oval. The cross section may have a trapezoidal shape having apair of sides substantially parallel to each other.

Yet in the foregoing device, when viewed in the viewing direction, thespacer may comprise a center of gravity of a cross section takenparallel to the major surface of the substrate, wherein an imaginarystraight line extending from the center and crossing any one of sides ofthe first, second, third and fourth openings forms an angle with thatside, the angle being smaller than 90°, wherein, when viewed in theviewing direction, two imaginary tangential lines extending from thecenter to any one of the first, second, third and fourth corners form anangle therebetween which is smaller than 90°. When viewed in the viewingdirection, the spacer may comprise a center of gravity of a crosssection taken parallel to the major surface of the substrate, wherein animaginary straight line extending from the center and passing any one ofthe first, second, third and fourth corners passes through thecorresponding opening comprising that corner. The third and fourthopenings may further comprise fifth and sixth corners, respectively,wherein the device further comprises an additional spacer disposedadjacent the fifth and sixth corners. The device may further comprise anadditional spacer having a cross section shape different from that ofthe spacer when the spacer and the additional spacer are cut in adirection parallel to the major surface of the substrate.

Further in the device, the spacer may be made of the same material asthe pixel defining layer. The device may further comprise first, second,third and fourth light emission layers formed over the first, second,third and fourth electrodes within the first, second, third and fourthopenings, respectively, wherein each light emission layer comprises anorganic light emission material. An area of the third opening may begreater than that of the first opening or the second opening. The first,second, third and fourth openings do not comprise any area overlappingthe imaginary polygon when viewed in the viewing direction. When viewedin the viewing direction, the substantially entire portion of the spacermay be enclosed within the imaginary polygon.

Still another aspect of the invention provides a method formanufacturing an organic light emitting diode display, which maycomprise: forming a plurality of electrodes over a substrate; forming apixel defining layer over the substrate and the plurality of electrodes,the pixel defining layer comprising a plurality of openings, each ofwhich is formed over a corresponding one of the plurality of electrodes,and overlaps the corresponding electrode when viewed in a viewingdirection perpendicular to a major surface of the substrate, wherein theplurality of electrodes comprises first, second, third and fourthelectrodes, wherein the plurality of openings comprises first, second,third and fourth openings overlapping the first, second, third andfourth electrodes, respectively, when viewed in a viewing directionperpendicular to the major surface, wherein the first, second, third andfourth openings comprise first, second, third and fourth corners,respectively, wherein the first, second, third and fourth cornersneighbor one another when viewed in the viewing direction; forming aspacer over the pixel defining layer, wherein, when viewed in theviewing direction, the spacer comprises at least a portion placed withinan imaginary polygon defined by the first, second, third and fourthcorners; and forming an organic light emission layer by depositing anorganic light emission material in each opening, wherein the forming ofthe spacer comprises: forming a receiving groove on the pixel defininglayer; applying a spacer forming material on the pixel defining layer;and making the spacer reflow to fill the spacer forming material in thereceiving groove.

In the foregoing method, while reflowing the spacer, a boundary of thespacer may be rounded. The plurality of electrodes may further comprisefifth and sixth electrodes, wherein the plurality of openings comprisefifth and sixth openings overlapping the fifth and sixth electrodes,respectively, when viewed in the viewing direction, wherein the devicecomprises first and second pixels, each of which comprises first, secondand third sub-pixels, the first, second and third sub-pixels configuredto emit colored light having colors different from one another, whereinthe first, third and fifth openings belong to the first, second andthird sub-pixels of the first pixel, respectively, wherein the second,fourth and sixth openings belong to the first, second and thirdsub-pixels of the second pixel, respectively, wherein the first, second,fifth and sixth openings are arranged such that their long sides aresubstantially parallel to each other when viewed in the viewingdirection, wherein the third and fourth openings are arranged such thattheir long sides are substantially aligned to an imaginary straight linewhen viewed in the viewing direction, wherein the first and fourthcorners are diagonally disposed and the second and third corners arediagonally disposed.

An embodiment of the present invention provides an organic lightemitting diode display, including: a substrate; a plurality ofelectrodes positioned on the substrate and including a first electrode,a second electrode, and a third electrode; a pixel defined layerpositioned on the plurality of electrodes and including a plurality ofopenings through which the plurality of electrodes are each exposed; anda spacer positioned on the pixel defined layer, wherein the pixeldefined layer includes a first pixel and a second pixel, the first pixeland the second pixel each includes: a first opening disposed along afirst direction and having the first electrode exposed therethrough; asecond opening disposed to be spaced apart from the first opening alongthe first direction and having the second electrode exposedtherethrough; and a third opening disposed to be spaced apart from thefirst opening and the second opening, respectively, along a seconddirection intersecting the first direction and having a third electrodeexposed therethrough, and the spacer is disposed in an area which isformed to abut to one corner of the first opening of the first pixel,one corner of the second opening of the second pixel, one corner of thethird opening of the first pixel, and one corner of the third opening ofthe second pixel, respectively.

The pixel defined layer may further include a receiving groove which isformed along a boundary abut to the pixel defined layer by the spacer toreceive a portion of the material forming the spacer.

The first opening, the second opening, and the third opening each mayhave a rectangular shape which is defined by a pair of sides disposed inparallel along the first direction and another pair of sides disposed inparallel along the second direction.

The spacer may include a radial center and a smaller angle among anglesformed by a straight line extending from the radial center and eachboundary among the first opening, the second opening, and the thirdopening may be from above 0° to under 90°.

The radial center may be the center of gravity of a cross section inwhich the spacer is cut in a direction parallel with the substrate.

The first opening, the second opening, and the third opening may eachinclude a plurality of corners which are formed in a curved line.

The cross section in which the spacer is cut in a direction parallelwith the substrate may be any one of a polygon, a circle, a semicircle,and an oval.

The cross section may be a trapezoidal shape having a pair of sidesparallel with the second direction.

The area may be formed on the pixel defined layer in any one of apolygon, a circle, a semicircle, and an oval.

A boundary of the spacer may externally contact, match, or internallycontact a boundary of the area or be completely included in the area.

The spacer may be disposed in pair to face each other with respect to acentral axis of the third opening formed in a direction parallel withthe second direction.

The spacer may be formed in plural and may have different cross sectionshapes in which the spacer is cut in a direction parallel with thesubstrate.

The spacer may be made of the same material as the pixel defined layer.

The first opening may be provided with a first emission layer depositedwith a first organic emission material, the second opening may beprovided with a second organic emission layer deposited with a secondorganic emission material, and the third opening may be provided with athird organic emission layer deposited with a third organic emissionmaterial.

An area of the third opening may be wider than that of the first openingand the second opening, respectively.

Another embodiment of the present invention provides a method formanufacturing an organic light emitting diode display, including:forming a plurality of electrodes including a first electrode, a secondelectrode, and a third electrode on a substrate; forming a pixel definedlayer on the substrate and the electrode so that a plurality of openingsare formed at positions corresponding to the plurality of electrodes,respectively, to expose the electrodes; forming a spacer in an area onthe pixel defined layer which is formed to abut to one corner of a firstopening of a first pixel, one corner of a second opening of a secondpixel, one corner of a third opening of the first pixel, and one cornerof a third opening of the second pixel, respectively; and forming anorganic emission layer by depositing an organic emission material in theopening, wherein the forming of the spacer includes: forming a receivinggroove along a boundary of a position corresponding to the shape of thespacer which is formed on the pixel defined layer; applying a materialforming the spacer; and making the spacer reflow to fill the materialforming the spacer in the receiving groove.

In the reflowing of the spacer, a boundary of the spacer may be rounded.

According to an embodiment of the present invention, it is possible toprovide the organic light emitting diode display and the method formanufacturing the same capable of remarkably reducing the possibility ofinvading the debris of the damaged spacer into the opening of the pixeldefining layer even though the spacer is damaged by the external impactto prevent the occurrence of defects of products, thereby remarkablyreducing the occurrence rate of defects of products.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating an organic light emitting diode displayaccording to an embodiment of the present invention.

FIG. 2 is a plan view of the organic light emitting diode display ofFIG. 1.

FIG. 3 is a cross-sectional view taken along the line II-II′ of FIG. 1.

FIG. 4 is a diagram illustrating an appearance before the organic lightemitting diode display of FIG. 1 reflows.

FIG. 5 is a plan view of the organic light emitting diode display ofFIG. 4.

FIG. 6 is a diagram illustrating an area in which a spacer according toan embodiment of the present invention may be formed.

FIGS. 7 to 10 are diagrams illustrating variously modified examples ofthe spacer.

FIG. 11 is a diagram illustrating the spacer having a radial centeraccording to the embodiment of the present invention.

FIG. 12 is a diagram for describing the radial center according to theembodiment of the present invention.

FIG. 13 is a diagram illustrating an example in which the radial centerof the embodiment of the present invention may not be formed.

FIGS. 14 and 15 are diagrams illustrating variously modified examples ofthe spacer.

FIG. 16 is a diagram illustrating an organic light emitting diodedisplay according to another embodiment of the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS

Hereinafter, embodiments of the present invention will be described indetail with reference to the drawings. However, in describingembodiments of the present invention, the description of well-knownfunctions or constructions will be omitted to make a gist of the presentinvention clear.

Hereinafter, an organic light emitting diode display according to anembodiment of the present invention will be described with reference tothe accompanying drawings.

In embodiments, an organic light emitting diode display includes a firstsubstrate, a plurality of pixel circuits, each including at least a thinfilm transistor, a plurality of pixels, each including a first electrodeconnected to a corresponding pixel circuit, a pixel definition layerhaving a plurality of openings through which a corresponding firstelectrode is exposed, and a plurality of spacers disposed on the pixeldefinition layer. Each pixel further includes an organic light emissionlayer disposed on or over the first electrode within the opening and asecond electrode disposed on or over the organic light emission layer. Asecond substrate is disposed on or over the second electrode.

In the above organic emitting diode display, the spacer is disposed in aspace between the plurality of openings which are set by the pixeldefinition layer and may serve to support a deposition mask during aprocess of depositing an organic material using the deposition mask.However, when the spacer is damaged due to an impact in a directionperpendicular to a display surface of the organic light emitting diodedisplay, debris of the damaged spacer invades the opening to cover anelectrode exposed through the opening, thereby causing defects of theorganic light emitting diode display and a reduction in performance.

FIG. 1 is a diagram illustrating an organic light emitting diode displayin which a spacer SP1 according to an embodiment of the presentinvention is formed, FIG. 2 is a plan view of the organic light emittingdiode display of FIG. 1, and FIG. 3 is a cross-sectional view takenalong the line II-II′ of FIG. 1.

FIG. 4 is a diagram illustrating an appearance before the organic lightemitting diode display of FIG. 1 reflows and FIG. 5 is a plan view ofthe organic light emitting diode display of FIG. 4.

According to an embodiment of the present invention, an organic lightemitting diode display which includes a substrate SU, electrodes E1, E2,and E3, a pixel defining layer PDL, and the spacer SP1 is provided.

The substrate SU is a base of the organic light emitting diode displayaccording to the embodiment of the present invention and may be made ofhard materials such as ceramic of glass, etc., metal, and syntheticresin or soft materials such as polyimide (PI). Therefore, the scope ofthe embodiment of the present invention is not limited by variousphysical properties such as a kind, a property, and a material ofsubstrate (SU).

The electrodes E1, E2, and E3 are disposed on or over the substrate SUand receive electrical signals to transfer electrons or holes to organicemission layers OL1, OL2, and OL3, thereby operating the organic lightemitting diode display.

The electrode may include metal, oxides such as indium tin oxide (ITO),and materials such as carbon nanotube (CNT) but the embodiment of thepresent invention is not limited thereto. Therefore, any materialthrough which electricity may be conducted may be included in the scopeof the present invention.

The electrodes E1, E2, and E3 according to the embodiment of theembodiment of the present invention may be formed in plural, including afirst electrode E1, a second electrode E2, and a third electrode E3. Inembodiments, each of the plurality of pixels of the display may includefirst, second and third sub-pixels which include the first electrode E1,the second electrode E2, and the third electrode E3, respectively. Thefirst, second and third sub-pixels emit colored light having colorsdifferent from one another.

In embodiment, the first electrode E1, the second electrode E2, and thethird electrode E3 according to the embodiment of the present inventionmay each be an anode which serves as a hole injection electrode or acathode which serves as an electron injection electrode. The firstelectrode E1, the second electrode E2, and the third electrode E3 may beformed as a light transmitting electrode, a light transflectiveelectrode, or a light reflective electrode.

A circuit layer FC may be formed between the substrate SU and theelectrodes E1, E2, and E3 according to the embodiment of the presentinvention. To transfer the electrical signals to the electrode, thecircuit layer FC may include a wiring which includes at least one scanline, a data line, a driving power supply line, a common power supplyline and the like, a pixel circuit which includes at least two thin filmtransistors (TFTs) and at least one capacitor connected to the wiringcorresponding to each pixel, and the like. In addition, the circuitlayer FC may have known various structures and the configuration of thecircuit layer FC does not limit the scope of the present invention.

The pixel defining layer (PDL) is disposed on or over the plurality ofelectrodes and includes a plurality of openings OM1, OM2, and OM3covering edges of the plurality of electrodes, respectively, to exposeeach electrode. In embodiments, the plurality of pixels includes a firstpixel PX1 and a second pixel PX2. For each of the first pixel PX1 andthe second pixel PX2, the pixel defining layer (PDL) according to theembodiment of the present invention includes the first opening OM1, thesecond opening OM2, and the third opening OM3. In embodiments, eachopening may be a hole which receives an organic light emission materialand other materials. In other embodiments, each opening may be a trenchwhich receives an organic light emission material and other materials.

The first opening OM1 is disposed along a first direction VL1 andexposes the first electrode E1. The first opening OM1 according to theembodiment of the present invention may be deposited with a firstorganic emission material to form a first organic emission layer OL1. Inembodiments, the first organic emission layer OL1 of the first openingOM1 according to the embodiment of the present invention may be formedby being deposited with the organic emission material representing anyone of red and green by excitons formed by a combination of electronsand holes when a voltage or a current is applied to the electrodescorresponding to each organic emission layer OL1, OL2, and OL3, but theembodiment of the present invention is not limited thereto, andtherefore it may be formed by an organic emission material representingany one of blue and white.

The second opening OM2 is spaced apart from the first opening OM1 alongthe first direction VL1 and exposes the second electrode E2. The secondopening OM2 according to the embodiment of the present invention may bedeposited with a second organic emission material to form the secondorganic emission layer OL2. In embodiments, the second organic emissionlayer OL2 of the second opening OM2 according to the embodiment of thepresent invention may be formed by being deposited with the organicemission material representing one color different from the firstorganic emission layer OL1 between red and green by excitons formed by acombination of electrons and holes when a voltage or a current isapplied to the electrodes corresponding to each organic emission layerOL1, OL2, and OL3, but the embodiment of the present invention is notlimited thereto, and therefore it may be formed by an organic emissionmaterial representing one color different from the first organicemission material among colors including blue or white.

The third opening OM3 is spaced apart from the first opening OM1 and thesecond opening OM2, respectively, along the second direction VL2intersecting the first direction VL1 and exposes the third electrode E3.The third opening OM3 according to the embodiment of the presentinvention may be deposited with a third organic emission material toform the third organic emission layer OL3. In embodiments, the thirdorganic emission layer OL3 of the third opening OM3 according to theembodiment of the present invention may be formed by being depositedwith the organic emission material representing blue by excitons formedby a combination of electrons and holes when a voltage or a current isapplied to the electrodes corresponding to each organic emission layerOL1, OL2, and OL3, but the embodiment of the present invention is notlimited thereto, and therefore it may be formed by an organic emissionmaterial representing any one of red, green and white.

Meanwhile, the third opening OM3 formed with the third organic emissionlayer OL3 representing a blue color according to the embodiment of thepresent invention may have an area wider than that of the first openingOM1 and the second opening OM2.

In addition thereto, the opening including the organic emission layerrepresenting a white color by being formed with a fourth opening may befurther provided and the scope of the present invention is not limitedthereto.

Each organic emission layer (first organic emission layer OL1, secondorganic emission layer OL2, and third organic emission layer OL3)according to the embodiment of the present invention is formed at aportion substantially deposited with the organic emission materialthrough an opening of a mask and when the electrodes corresponding toeach organic emission layer OL1, OL2, and OL3 are applied with voltageor current, they emit light with a predetermined color.

However, each organic emission material (first organic emissionmaterial, second organic emission material, third organic emissionmaterial) is deposited through the opening of the mask and is thusdeposited at the position corresponding to the opening of the mask.Therefore, each organic emission material may be deposited to have anarea wider than that of the openings OM1, OM2, and OM3 of the pixeldefining layer (PDL) and the organic emission material may also bepositioned on or over the pixel defining layer (PDL) and the spacer SP1to be described below. However, in the drawings and the detaileddescription for describing the embodiment of the present invention, aportion at which the organic light emission material is deposited andwill emit light depending on the application of voltage or current isdefined as the organic emission layers OL1, OL2, and OL3.

The spacer SP1 may support the deposition mask while each organicemission material corresponding to each opening OM1, OM2, and OM3 isdeposited and may support components which are formed at an upperportion even when the following processes are performed.

The spacer SP1 according to the embodiment of the present invention isdisposed in the areas AR1 and AR2 which are each abut to one corner ofthe first opening OM1 of the first pixel PX1, one corner of the secondopening OM2 of the second pixel PX2, one corner of the third opening OM3of the first pixel PX1, and one corner of the third opening OM3 of thesecond pixel PX2.

In embodiments, when defining two-dimensionally in the detaileddescription of the present application, a ‘corner’ may include anintersecting point or portion of two side lines forming the boundary ofeach of the openings OM1, OM2, and OM3 when viewing the first openingOM1, the second opening OM2, and the third opening OM3, respectively, ina vertical direction to the substrate SU. Alternatively, definingthree-dimensionally, corners on two dimension mean intersecting pointswhich are formed by three-dimensionally intersecting each other. In oneembodiment, each opening may include a sharp corner when viewed in aviewing direction perpendicular to a major surface of the substrate. Inanother embodiment, each opening may include a rounded corner whenviewed in the viewing direction.

However, the embodiment of the present invention is not limited thereto.In alternative embodiments, the areas AR1 and the AR2 do not abut to anyone of the foregoing four corners. Further, even the case in which theareas AR1 and AR2 are formed by each connecting the second opening OM2and the third opening OM3 of the first pixel PX1 and the first openingOM1 and the third opening OM3 of the second pixel PX2 may be easilyderived from the embodiment of the present invention, which may beincluded in the scope of the present invention.

FIG. 6 illustrates that in the organic light emitting diode displayaccording to the embodiment of the present invention, the areas AR1 andAR2 in which the spacer SP1 may be formed are represented on the pixeldefining layer (PDL) and FIGS. 7 to 10 are diagrams illustratingvariously modified examples of the spacer and the area.

The areas AR1 and AR2 may be a polygon such as a quadrangle asillustrated in FIG. 6 but are not limited thereto and therefore may beformed in any one shape of a circle, a semicircle, and an oval. Further,these shapes are only examples for describing various embodiments of thepresent invention and therefore any shape which may be implemented twodimensionally or three dimensionally or the areas AR1 and AR2 forforming the spacer SP1 at the same or similar position to achieve thesame or similar purpose as or to the present invention may be allowable,which does not limit the scope of the present invention.

In embodiments, the pixel defining layer (PDL) according to theembodiment of the present invention may further include a receivinggroove FH.

The receiving groove FH is a groove formed along a boundary to which thespacer SP1 abuts to the pixel defining layer (PDL) in an oppositedirection to a direction in which the spacer SP1 is formed based on thepixel defining layer (PDL). Therefore, a portion of the spacer SP1 maybe received in a portion or all of the receiving groove FH by a processof making the spacer SP1 reflow.

FIGS. 4 and 5 illustrate an appearance of the spacer SP1 before thereflow process is performed and FIGS. 1 to 3 illustrate an appearance ofthe spacer SP1 after the reflow process is performed.

As illustrated in FIGS. 4 and 5, the spacer SP1 is formed to expose thereceiving groove FH to the outside before the reflow process isperformed, but when the reflow process is performed, as illustrated inFIGS. 1 to 3, the spacer SP1 may be filled in the receiving groove FH.

Therefore, the boundary of the spacer SP1 according to the embodiment ofthe present invention may be defined by the shape of the receivinggroove FH and the spacer SP1 maintain its own shape by not being meltedor flowing along the surface of the pixel defining layer (PDL) at thetime of performing the reflow process and being received in a portion orall of the receiving groove FH.

The first opening OM1, the second opening OM2, and the third opening OM3according to the embodiment of the present invention may each have arectangular shape which is defined by a pair of sides disposed inparallel along the first direction VL1 and another pair of sidesdisposed in parallel along the second direction. Here, “disposed inparallel” does not mean complete parallelism, but parallelism enough tobe determined as being parallel at a generally recognized level may beincluded in the scope of the present invention.

Meanwhile, FIGS. 7 to 10 illustrate the area AR1 and the spacer SP1according to various embodiments of the present invention.

As illustrated in FIGS. 7 to 10, a cross section of the spacer SP1according to the embodiment of the present invention which is cut in aparallel direction with the substrate SU may be a polygon such as aquadrangle, a pentagon, and a hexagon or any one of a circle, asemicircle, and an oval.

Further, the spacer SP1 according to the embodiment of the presentinvention externally contacts, matches, or internally contacts aboundary of the area AR1 which abuts to one corner of the first openingOM1 of the first pixel PX1, one corner of the second opening OM2 of thesecond pixel PX2, one corner of the third opening OM3 of the first pixelPX1, and one corner of the third opening OM3 of the second pixel PX2,respectively, or is completely included in the area AR1, therebypreventing the boundary of the area AR1 and the boundary of the spacerSP1 from intersecting each other.

Therefore, as illustrated in the foregoing contents and each drawing, inembodiments, the shape of the cross section may be freely changed aslong as the spacer SP1 according to the embodiment of the presentinvention may be formed in the area AR1 which abuts to one corner of thefirst opening OM1 of the first pixel PX1, one corner of the secondopening OM2 of the second pixel PX2, one corner of the third opening OM3of the first pixel PX1, and one corner of the third opening OM3 of thesecond pixel PX2. The intersection of the spacer SP1 with the area AR1may be included in the scope of the present invention, regardless ofwhether a portion of the spacer SP1 intersects the area AR1 or iscompletely included in the corresponding area AR1. Further, in additionto embodiments which are described and illustrated in the detaileddescription of the present invention, there may be variously modifiedexamples which may be included in the scope of the present invention.

As one of the embodiments of the present invention, FIG. 2 illustratesthat the boundary of the area AR1 matches the boundary of the spacer SP1while abutting to the first opening OM1 and the third opening OM3 of thefirst pixel PX1, the second opening OM2 and the third opening OM3 of thesecond pixel PX2, respectively, and the spacer SP1 having a trapezoidalcross section in which a side which connects the first opening OM1 ofthe first pixel PX1 and the second opening OM2 of the second pixel PX2and a side which connects the third opening OM3 of the first pixel PX1and the third opening OM3 of the second pixel PX2 are disposed inparallel along the second direction VL2 is illustrated.

In embodiments, as described above, the first opening OM1, the secondopening OM2, and the third opening OM3 may each have a rectangularshape.

An organic light emitting diode display according to another embodimentof the present invention includes a radial center (RC) which is formedat a center of the spacer SP1. In the detailed description of thepresent application, the “radial center (RC)” means a reference pointwhich is a center radially extending from any one point.

FIG. 11 is a diagram illustrating the spacer SP1 having the radialcenter (RC) according to the embodiment of the present invention andFIGS. 12 and 13 illustrate an example in which the radial centeraccording to the embodiment of the present invention may be formed andan example in which the radial center according to the embodiment of thepresent invention may not be formed. FIGS. 14 and 15 illustrate that thespacer SP1 may have the radial center RC regardless of the shape andsize of the area AR1 and the spacer SP1.

As illustrated in FIG. 11, according to the embodiment of the presentinvention, a smaller angle among angles formed by the boundaries of thefirst opening OM1, the second opening OM2, and the third opening OM3from the radial center RC of the spacer SP1 may be from above 0° tounder 90°

In the detailed description of the present application, the above angleis defined as an “incident angle”. According to the embodiment of thepresent invention, the incident angle which is the smaller angle amongangles formed by the boundaries of the first opening OM1, the secondopening OM2, and the third opening OM3 from the radial center RC of thespacer SP1 may be from above 0° to under 90°.

Therefore, as partially illustrated in FIG. 12 and as illustrated inFIG. 13, when the incident angle is 0° or 90°, the radial centeraccording to the embodiment of the present invention may not be formed.When the incident angle is 0° or 90° in any one direction amongdirections radially extending from the radial center RC, the spacer SP1according to the embodiment of the present invention may not be disposedat the corresponding position.

Therefore, the radial center RC of the oval area AR1 in FIG. 12 or allthe radial centers RCs illustrated in FIG. 13 include a point at whichthe incident angle to any one of the first opening OM1, the secondopening OM2, and the third opening OM3 is 0° or 90° and therefore maynot be the radial center according to the embodiment of the presentinvention.

The embodiment of the present invention is based on the fact that a pairof boundaries among the boundaries among the first opening OM1, thesecond opening OM2, and the third opening OM3, respectively, has arectangular shape parallel with the first direction VL1 and the seconddirection VL2, respectively, to define the incident angle but is notlimited thereto and therefore any opening OM1, OM2, and OM3 having ashape for measuring the incident angle may be easily derived from thoseskilled in the art, and therefore the modification thereof may also beincluded in the scope of the present invention.

Further, the first opening OM1, the second opening OM2, and the thirdopening OM3, respectively, according to the embodiment of the presentinvention may include a plurality of corners which is formed in a curvedline. As described above, when the boundaries among the opening OM1,OM2, and OM3, respectively, have a curved line, the incident angle maybe obtained by obtaining the curvature radius for the curved line andmeasuring an angle between a tangential line of a circular arc based onthe corresponding curvature radius and the direction extending from theradial center RC.

In embodiments, the area AR1 and the spacer SP1 according to theembodiment of the present invention may have the radial center RCregardless of the shape and the size as illustrated in FIGS. 14 and 15.In embodiments, the radial center RC may be a center of gravity having across section in which the spacer SP1 is cut in a direction parallelwith the substrate SU. However, this is only the embodiment of thepresent invention and unlike FIGS. 14 and 15, in the case of the spacerSP1 having a polygonal cross section, the intersecting point at whichthe polygonal diagonal lines coincide with each other may also be theradial center RC.

Any one point which is present in the cross section of the spacer SP1other than the boundary of the spacer SP1 may be the radial center RCaccording to the embodiment of the present invention and as illustratedin FIGS. 11 to 15, the radial center RC according to the embodiment ofthe present invention may be disposed at the boundary of the first pixelPX1 and the second pixel PX2, respectively, but the present invention isnot limited thereto and therefore the radial center RC may also bepresent in any one pixel.

According to the foregoing embodiments of the present invention, theorganic light emitting diode display, which may have an area as large aspossible within the areas AR1 and AR2 in which the spacer SP1 accordingto the embodiment of the present invention may be disposed and thespacer SP1 in which the occurrence of defects that the damaged debris ofthe spacer SP1 due to the external impact covers the vision of theopenings OM1, OM2, and OM3 is reduced, may be provided.

Meanwhile, the spacer SP1 according to the embodiment of the presentinvention may be disposed in pair to face each other with respect to acentral axis VCL of the third opening OM3 which is formed in a paralleldirection with the second direction VL2. Therefore, as illustrated inFIGS. 2, 5, and 6, in the spacer SP1 according to the embodiment of thepresent invention, one spacer SP1 which is formed in a total of twopixels over one first pixel PX1 and one second pixel PX2 and one spacerSP1 which is formed in a total of four pixels over two first pixels PX1and two second pixels PX2 may be disposed to face each other withrespect to the central axis VCL of the third opening OM3.

Here, “facing” means that the spacer SP1 may be disposed at both sidesbased on the central axis VCL and does not mean that distances from thecentral axis VCL to a place where the spacer SP1 is disposed or thecross section of each spacer SP1 is completely the same. Therefore, thecase in which the distance from the central axis VCL to a place wherethe spacer SP1 is disposed is slightly different or the cross section ofeach spacer SP1 disposed at both side with respect to the central axisVCL is different from each other may be included in the scope of thepresent invention.

FIG. 16 illustrates a disposition of the spacers SP1 and SP2 accordingto a modified embodiment of the present invention. According to themodified example of the present invention, the third opening OM3 formedin the pixel defining layer (PDL) is formed to have a period for whichit is repeated over at least two pixels. FIG. 16 illustrates a periodfor which a disposition of the third opening OM3 is repeated over twopixels.

Therefore, as illustrated in FIG. 16, a size or a shape of the areas AR1and AR2 in which the spacers SP1 and SP2 may be formed are repeated overat least two pixels and the spacers SP1 and SP2 having different crosssections may be formed in each region AR1 and AR2.

Meanwhile, the spacer SP1 according to the embodiment of the presentinvention may be made of the same material as the pixel defining layer(PDL). For example, the spacer SP1 may be made of the same material aspolymer and may be made of a material having different physicalproperties.

The organic light emitting diode display according to the embodiment ofthe present invention as described above may remarkably reduce thepossibility of invading the debris of the damaged spacer SP1 into theopenings OM1, OM2, and OM3 of the pixel defining layer (PDL) even thoughthe spacer SP1 is damaged by the external impact to reduce theoccurrence of defects of products, thereby remarkably reducing theoccurrence rate of defects of products.

Hereinafter, a method for manufacturing an organic light emitting diodedisplay according to another embodiment of the present invention will bedescribed.

According to the embodiment of the present invention, a method formanufacturing an organic light emitting diode display includes formingthe electrode on or over the substrate (SU), forming the pixel defininglayer (PDL), forming the spacer SP1, and forming the organic emissionlayers OL1, OL2, and OL3.

The forming of the electrode over the substrate (SU) is forming theelectrode of a conductive material over a hard or soft substrate (SU)including materials such as ceramic, metal, or synthetic resin.

The electrode may include metal, oxides such as indium tin oxide (ITO),and materials such as carbon nanotube (CNT) but the embodiment of thepresent invention is not limited thereto. Therefore, any materialthrough which electricity may be conducted may be included in the scopeof the present invention.

Meanwhile, the forming of the circuit layer FC on or over the substrate(SU) may be first performed before the forming of the electrodeaccording to the embodiment of the present invention is performed. Thecircuit layer FC may be formed to be electrically connected to theelectrode by the known method to transfer the electrical signal to theelectrode.

In embodiments, as the electrode formed on or over the substrate (SU)according to the embodiment of the present invention, a plurality ofelectrodes including the first electrode E1, the second electrode E2,and the third electrode E3 may be formed.

The forming of the pixel defining layer (PDL) is forming the pixeldefining layer (PDL) including the plurality of openings OM1, OM2, andOM3 through which the plurality of electrodes are exposed. Inembodiments, each opening OM1, OM2, and OM3 is formed after a layer ofthe pixel defining layer (PDL) material is formed or may besimultaneously formed with forming the pixel defining layer (PDL) bydesignating a position at which the opening OM1, OM2, and OM3 are formedin advance. However, the embodiment of the present invention is notlimited thereto. The forming of the openings OM1, OM2, and OM3 may beperformed based on various modified examples.

The forming of the spacer SP1 is forming the spacer SP1 in the areas AR1and AR2 on the pixel defining layer (PDL) which abuts to one corner ofthe first opening OM1 of the first pixel PX1, one corner of the secondopening OM2 of the second pixel PX2, one corner of the third opening OM3of the first pixel PX1, and one corner of the third opening OM3 of thesecond pixel PX2.

However, in alterative embodiments, the areas AR1 and the AR2 do notabut to any one of the foregoing four corners. Further, even the case inwhich the areas AR1 and AR2 are formed by connecting the second openingOM2 and the third opening OM3 of the first pixel PX1 and the firstopening OM1 and the third opening OM3 of the second pixel PX2, may beeasily derived from the embodiment of the present invention, which maybe included in the scope of the present invention.

In embodiments, the forming of the spacer SP1 according to theembodiment of the present invention includes forming the receivinggroove (FH), applying the spacer SP1 material, and making the spacer SP1reflow.

The forming of the receiving groove (FH) is forming the receiving groove(FH) which is partially or completely filled with the spacer SP1reflowing in the making the spacer SP1 reflow which will be describedbelow on the pixel defining layer PDL of the position corresponding tothe shape of the spacer SP1. The boundary may be clearly formed by thereceiving groove (FH) even though the spacer SP1 according to theembodiment of the present invention is subjected to the reflowing.

The applying of the spacer SP1 material is applying a material formingthe spacer SP1 in the boundary of the spacer SP1 formed on the pixeldefining layer (PDL) by the receiving grove (FH). In embodiments, thespacer SP1 according to the embodiment of the present invention may bemade of the same material as the pixel defining layer (PDL), but is notlimited thereto.

As described above, FIGS. 4 and 5 illustrate an appearance in which thespacer SP1 material is applied within the boundary area formed by thereceiving groove (FH). As illustrated in FIGS. 4 and 5, since the reflowprocess is not yet performed, the spacer SP1 material is not yet filledin the receiving groove (FH), and therefore the receiving groove (FH) isexposed to the outside.

The reflowing of the spacer SP1 is improving an adhesion of the spacerSP1 formed by heating the applied spacer SP1 material.

In embodiments, according to the embodiment of the present invention, inthe reflowing of the spacer SP1, the spacer SP1 is heated and thus thematerial forming the spacer SP1 may have flowability. Therefore, thematerial forming the spacer SP1 may have a changed shape in a directionin which the surface energy is reduced depending on thermodynamics laws.

Generally, the shape which may minimize the surface energy is aspherical shape in the case of three dimension or a circular shape inthe case of two dimension. However, in embodiments, the material wouldnot be formed by a complete spherical shape or circular shape due to thephysical properties of the material and the external environments suchas reflow temperature, but the scope of the present invention mayinclude the case in which the spacer SP1 is not formed in a completespherical shape or circular shape.

Therefore, when the spacer SP1 is heated, the spacer SP1 is deformed toapproach the possible spherical shape or circular shape, the boundary orcorner of the spacer SP1 may be rounded, or the boundary having thecross section of the spacer SP1 may be rounded.

Further, according to the embodiment of the present invention, when thespacer SP1 is heated, the spacer SP1 material having flowability flowsin the receiving groove (FH) and thus all or a portion of the receivinggroove (FH) may be filled.

As described above, FIGS. 1 to 3 illustrate that the receiving groove(FH) is filled by performing the reflow process and the surface of thespacer SP1 is rounded. The receiving groove (FH) is filled by making thespacer SP1 material flowing in the receiving groove (FH) and thus theboundary of the spacer SP1 is defined by the receiving groove (FH) to beclearly formed without being dispersed.

Meanwhile, the forming of the organic emission layers OL1, OL2, and OL3is forming the organic emission layers OL1, OL2, and OL3 by depositingthe organic emission material in the openings OM1, OM2, and OM3 formedin the pixel defining layer (PDL).

In embodiments, when the organic emission layers OL1, OL2, and OL3according to the embodiment of the present invention is applied withelectricity, the first opening OM1, the second opening OM2, and thethird opening OM3 may be each formed to represent different colors.

To form the organic emission layers OL1, OL2, and OL3, the mask of whichthe positions corresponding to each opening OM1, OM2, and OM3 are openedmay be used and when the organic emission material is deposited, themask may be supported by the spacer SP1.

The organic light emitting diode display according to the embodiment ofthe present invention may be manufactured by forming the organicemission layers OL1, OL2, and OL3 and then forming the electrode again,and sealing the upper portion of the substrate (SU) including the spacerSP1 and the pixel defining layer.

Hereinabove, the organic light emitting diode display according to theembodiment of the present invention and the method for manufacturing thesame according to another embodiment of the present invention aredescribed.

According to an embodiment of the present invention, it is possible toprovide the organic light emitting diode display and the method formanufacturing the same capable of remarkably reducing the possibility ofinvading the debris of the damaged spacer SP1 into the openings OM1,OM2, and OM3 of the pixel defining layer (PDL) even though the spacerSP1 is damaged by the external impact to reduce the occurrence ofdefects of products, thereby remarkably reducing the occurrence rate ofdefects of products.

As described above, embodiments of the present invention are describedwith reference to the drawings, but the present invention is not limitedto the above-mentioned embodiments. Therefore, the present invention isnot limited to the above embodiments and can be variously changed andmodified from the description by a person skilled in the art to whichthe present invention pertains.

Therefore, the modified examples or the changed examples are not to beindividually construed from the technical spirit of the presentinvention and therefore the modified embodiments are to be construed tobe included in claims of the present invention.

While this invention has been described in connection with what ispresently considered to be practical embodiments, it is to be understoodthat the invention is not limited to the disclosed embodiments, but, onthe contrary, is intended to cover various modifications and equivalentarrangements included within the spirit and scope of the appendedclaims.

What is claimed is:
 1. An organic light emitting diode display,comprising: a substrate comprising a major surface; a plurality ofelectrodes positioned over the substrate; a pixel defining layerpositioned over the plurality of electrodes and comprising a pluralityof openings, each of which is disposed over and overlaps one of theplurality of electrodes; and a spacer positioned over the pixel defininglayer and formed of polymer, wherein the plurality of electrodescomprises first, second, third and fourth electrodes, wherein theplurality of openings comprises first, second, third and fourth openingsoverlapping the first, second, third and fourth electrodes,respectively, when viewed in a viewing direction perpendicular to themajor surface, wherein the first, second, third and fourth openingscomprise first, second, third and fourth corners, respectively, whereinthe first, second, third and fourth corners neighbor one another whenviewed in the viewing direction, wherein, when viewed in the viewingdirection, the spacer comprises at least a portion placed within animaginary polygon defined by the first, second, third and fourth cornersand wherein the cross section in which the spacer is cut in a directionparallel to the major surface of the substrate has a trapezoidal shapehaving a pair of sides substantially parallel to each other and anotherpair of sides not parallel to each other.
 2. The device display of claim1, wherein the plurality of electrodes further comprise fifth and sixthelectrodes, wherein the plurality of openings comprise fifth and sixthopenings overlapping the fifth and sixth electrodes, respectively, whenviewed in the viewing direction, wherein the device comprises first andsecond pixels, each of which comprises first, second and thirdsub-pixels, the first, second and third sub-pixels configured to emitcolored light having colors different from one another, wherein thefirst, third and fifth openings belong to the first, second and thirdsub-pixels of the first pixel, respectively, wherein the second, fourthand sixth openings belong to the first, second and third sub-pixels ofthe second pixel, respectively, wherein the first, second, fifth andsixth openings are arranged such that their long sides are substantiallyparallel to each other when viewed in the viewing direction, wherein thethird and fourth openings are arranged such that their long sides aresubstantially aligned to an imaginary straight line when viewed in theviewing direction, wherein the first and fourth corners are diagonallydisposed, and the second and third corners are diagonally disposed. 3.The display of claim 2, wherein, when viewed in the viewing direction,the spacer does not comprise a portion disposed between the first andsecond openings, between the first and third openings, between thesecond and fourth openings or between the third and fourth openings. 4.The display of claim 1, wherein each of the first, second, third andfourth openings has a generally rectangular shape, wherein, when viewedin the viewing direction, the first and second openings are arrangedsuch that their long sides are substantially parallel to a firstdirection and the third and fourth openings are arranged such that theirlong sides are substantially parallel to a second direction which isperpendicular to the first direction.
 5. The display of claim 1, whereineach of the first, second, third and fourth corners is rounded.
 6. Thedisplay of claim 1, wherein, when viewed in the viewing direction, thespacer comprises a center of gravity of a cross section taken parallelto the major surface of the substrate, wherein an imaginary straightline extending from the center and crossing any one of sides of thefirst, second, third and fourth openings forms an angle with that side,the angle being smaller than 90°, wherein, when viewed in the viewingdirection, two imaginary tangential lines extending from the center toany one of the first, second, third and fourth corners form an angletherebetween which is smaller than 90°.
 7. The display of claim 1,wherein, when viewed in the viewing direction, the spacer comprises acenter of gravity of a cross section taken parallel to the major surfaceof the substrate, wherein an imaginary straight line extending from thecenter and passing any one of the first, second, third and fourthcorners passes through the corresponding opening comprising that corner.8. The display of claim 1, wherein the third and fourth openings furthercomprise fifth and sixth corners, respectively, wherein the devicefurther comprises an additional spacer disposed adjacent the fifth andsixth corners.
 9. The display of claim 1, further comprising anadditional spacer having a cross section shape different from that ofthe spacer when the spacer and the additional spacer are cut in adirection parallel to the major surface of the substrate.
 10. Thedisplay of claim 1, wherein the spacer is made of the same material asthe pixel defining layer.
 11. The display of claim 1, further comprisingfirst, second, third and fourth light emission layers formed over thefirst, second, third and fourth electrodes within the first, second,third and fourth openings, respectively, wherein each light emissionlayer comprises an organic light emission material.
 12. The display ofclaim 1, wherein an area of the third opening is greater than that ofthe first opening or the second opening.
 13. The display of claim 1,wherein the first, second, third and fourth openings do not comprisesany area overlapping the imaginary polygon when viewed in the viewingdirection.
 14. The display of claim 1, wherein, when viewed in theviewing direction, the substantially entire portion of the spacer isenclosed within the imaginary polygon.
 15. The device of claim 1,wherein the pixel defining layer further comprises a receiving groovewhich is formed along a boundary abutting to the pixel defining layer bythe spacer to receive at least a portion of the spacer.
 16. An organiclight emitting diode display, comprising: a substrate comprising a majorsurface; a plurality of electrodes positioned over the substrate andincluding a first electrode, a second electrode, and a third electrode;a pixel defining layer positioned over the plurality of electrodes andcomprising a plurality of openings, each of which is disposed over andoverlaps one of the plurality of electrodes; and a spacer positionedover the pixel defining layer and formed of polymer, wherein the pixeldefining layer includes a first pixel and a second pixel, wherein thefirst pixel and the second pixel each includes: a first opening disposedalong a first direction and having the first electrode exposedtherethrough; a second opening disposed to be spaced apart from thefirst opening along the first direction and having the second electrodeexposed therethrough; and a third opening disposed to be spaced apartfrom the first opening and the second opening, respectively, along asecond direction intersecting the first direction and having a thirdelectrode exposed therethrough, wherein the spacer is disposed in anarea which is formed to abut to one corner of the first opening of thefirst pixel, one corner of the second opening of the second pixel, onecorner of the third opening of the first pixel, and one corner of thethird opening of the second pixel, respectively, and wherein the crosssection in which the spacer is cut in a direction parallel to the majorsurface of the substrate has a trapezoidal shape having a pair of sidessubstantially parallel to each other and another pair of sides notparallel to each other.
 17. The display of claim 16, wherein, each ofthe first, second and third openings has a generally rectangular shape,wherein, when viewed in the viewing direction, the first and secondopenings are arranged such that their long sides are substantiallyparallel to a first direction and the third opening is arranged suchthat their long sides are substantially parallel to a second directionwhich is perpendicular to the first direction, and the spacer comprisesa center of gravity of a cross section taken parallel to the majorsurface of the substrate, wherein an imaginary straight line extendingfrom the center and crossing any one of sides of the first, second andthird openings forms an angle with that side, the angle being smallerthan 90°, wherein, when viewed in the viewing direction, two imaginarytangential lines extending from the center to any one of the first,second and third openings form an angle therebetween which is smallerthan 90°.
 18. The display of claim 16, wherein the pixel defining layerfurther comprises a receiving groove which is formed along a boundaryabutting to the pixel defining layer by the spacer to receive at least aportion of the spacer.